DIY manual pipe bender for a profile pipe

Recommendation points

• We select materials for the bed
• Rolling rolls – buy or make
• Clamping mechanism
• Synchronized drive
• How to improve the machine

For many home craftsmen, a pipe bending device would be very useful, but not everyone can afford to buy such a machine. You can go the other way and assemble a manual pipe bender for a profile pipe from available materials at hand, having basic metalworking skills and using our instructions.

We select materials for the bed

Although small force rolling is used to bend the pipes, the base of the machine must be strong and stable. Sometimes it makes sense to fix the tool on a hard floor so that when processing massive parts of complex shapes, the installation does not tip over..

One simple rule will help you choose the right material: the frame in terms of its structural capacity must be comparable to the pipe being processed, otherwise the machine itself will deform. If the bed is made up of several elements, they must have both longitudinal and transverse stiffeners.

In everyday life, the easiest way to get hold of corner steel is 80x80x7, 100x100x8 or so. From four segments 60–80 cm long, two T-shaped parts are welded, with such an assembly, they can (and should!) Be welded well along both longitudinal seams. The resulting profiles are connected by two overlays at the front and rear. The overhead corner with a length of 320–400 mm (depending on the width of the shelves) is applied with the edge upwards, thus obtaining a convenient plane in order to make a high-quality connection and obtain 2 transverse stiffeners. Another 4–5 short (160–200 mm) pieces of angle steel are installed from below for even better fastening of the halves to each other and imparting lateral rigidity.

For a reliable connection, it is preferable to weld the parts from the inside out, spreading them out on a known flat surface. Remember that the parts “lead” from welding, so first we assemble the frame with 5–6 mm tacks, level it, and then weld it completely. It is noteworthy that in the absence of welding, the connection can be made with bolts, but they must have a diameter of at least 12-14 mm, that is, it becomes difficult to drill.

Rolling rolls – buy or make

Many pipe bender projects imply the use of ball bearings, which is not entirely true. Their minus is the inability to withstand a significant radial load, the bearings will “roll” quickly enough, with the exception of roller and multi-row.

You won’t regret it if you bother to find the polyurethane or polyamide rollers that are commonly found among truck trolley accessories. The optimal standard size is 60–80×90–100 mm, that is, oblong. The bearing inside must be, as we have already found out, roller and maintenance-free. There may be no bearing at all, we will consider this option..

Rolls with polymer lining are free from the drawback of steel – they practically do not slip on the part during operation. Such a machine can also bend chrome-plated or painted parts without damaging the coating. There is no need to worry about durability – wheeled products of the described standard sizes are designed for a load of 0.75–1 ton and more, that is, the machine will be able to withstand a downforce of at least 2 tonnes, which is quite enough.

Note:no one denies the advantages of metal rolls, in general they are even better than polyurethane rolls. But it is quite difficult to find special rollers for pipe benders in the range of accessories, and not everyone can make them, besides, their surface must be carburized.

The design in question is adapted for rolling square shaped pipes, but having several sets of rollers with different surface shapes, it is possible to successfully bend both oval and round pipes, and even a complex profile, if necessary. Well, there are many ways to give the video the desired form factor, an extra reason to visit a familiar turner.

Clamping mechanism

We divide the bed in half along the length and mark the location of the vertical struts at the side edges. We make them from pieces of the same corner as on the bed, folding them in a square. The racks need to be shifted a little closer to the center, by about 20-25 mm. Thus, a lumen width of 120–160 mm is obtained. More than enough.

It’s easy to calculate the height of the racks. The diameter of the two rollers, the clearance for a pipe of 100–120 mm and another 100 mm for a free wheel – a total of approximately 400–450 mm. Vary this value depending on the size of the compression mechanism used. The racks are covered with a crossbeam with a vertical stiffener. For these purposes, it is good to acquire a small section of a channel 70x40x8 mm.

The second part of the mechanism is the basis for securing the pressure roller. It is better to make it in the form of a frame from a corner of a nominal size, which will slide along the racks as along the guides. A clamping mechanism is located between the frame and the crossbar. It can be an ordinary trapezoidal screw or an automobile hydraulic jack – you yourself choose the type and method of fastening, since the conditions of the bed allow you to do this in several ways.

The roller is attached under the frame at two regular corners, turned towards each other with axle holes in the vertical shelves. The roller on the pressure mechanism can be used with a bearing, but the drive ones are arranged a little differently.

Synchronized drive

One of the drawbacks of rolls with bearings is the difficulty of transmitting the rotating force. In fact, it is much easier to place a roll without a bearing on a hardened pin of the corresponding diameter, and it in two housing bearings rigidly fixed to the bed. Typically, the height of the shaft for such bearings is quite consistent with the radius of the polyurethane rollers; they fit with a margin of 15–20 mm without additional linings. Two rollers without a bearing are attached at different ends of the bed so that in the lateral projection the indents between the extreme and central rollers are 1.5-2 of their own diameters.

If you are practicing a professional approach, make small slots 120–140 mm long in the bed to adjust the position of the rollers depending on the thickness of the workpiece and the desired bend radius. This will also require the installation of a tension roller for the chain, the slack of which will constantly change..

The drive mechanism itself is extremely simple: the studs on both sides are limited by retaining rings, the grooves can be cut with a drill and a hacksaw for metal. On one side, the studs protrude about 40–60 mm, and are welded to the usual single-row chain sprockets. Before welding dissimilar metals, it may be helpful to warm them up slightly and release them..

The drive lever is made with a conventional knob, one axis of which is fixed in a tube of approximately equal inner diameter. It is enough just to weld it under the bottom of the bed, thread the knob and fix its end with a retaining ring. Naturally, the drive sprocket must first be fitted and welded onto the axle. The sprockets for tension and damping of the chain can be fixed directly in the bed, in this case the gear under the chain must have a hub to fit on the shaft or bearing. The axis of the damper is easily welded to the inner flange of the extreme corner of the bed.

How to improve the machine

The pipe bender of the described design is in no way inferior to analogs sold on the market: durable, reliable, components are easy to get. For greater convenience, it is recommended to raise it to the level of the belt, fixing it on a workbench or installing it on legs. Also, pipe slope limiters will not be superfluous, so that the bend is carried out in a circle, and not in a spiral.

Remember that the machine you make is a fairly solid base with good upgrade potential. If you are planning serial production or want to improve accuracy, supplement the machine with a simple hydraulic system to make rolling easier and more even.